Cryptography Concepts

Match the question with the correct answer.

For a receiver to decrypt a secret message sent to it, which key is used?

Receiver’s public key

To check whether the sender has ownership of the private key, which key is it decrypted with?

Sender’s private key

For a sender to prove ownership of a private key, which key is the message encrypted with?

Sender's public key

To send a secret message from sender to receiver, which key is it encrypted with?

Receiver’s private key

Homomorphic encryption is the technique where:

Plaintext and ciphertext are the same

Operations are performed on encrypted ciphertext

Sender and receiver share a secret key for encryption and decryption

Multiple encryptions on the same plaintext always result in the same ciphertext

The output of a hash function:

Is the same length as the input.

Is a constant length regardless of the input length.

What is Avalanche Effect?

A significant change in the input results in a significant change in the output

A small change in the input results in a small change in the output

A small change in the input results in a significant change in the output, making it statistically indistinguishable from random.

A small change in input makes the output statistically random

Match the questions to the correct answers

What is collision resistance in hash functions?

Given an input message and its hash, it is hard to find a different input message with the same hash.

What is second pre-image resistance in hash functions?

It is computationally hard to reverse a hash function

What is pre-image resistance in hash functions?

Given an input message and its hash, it is hard to find a different input message with the same hash.

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